Velocity Reviews

Velocity Reviews (http://www.velocityreviews.com/forums/index.php)
-   Cisco (http://www.velocityreviews.com/forums/f27-cisco.html)
-   -   iBGP Advertisements (http://www.velocityreviews.com/forums/t550446-ibgp-advertisements.html)

Ryan 11-09-2007 12:06 AM

iBGP Advertisements
 
I'm pretty new to the world of BGP. I have two main routers as a
small ISP, each with a connection to an upstream carrier. I'm using
address space provided by one of those carriers and the two main
routers are on different subnets. All appears well with the eBGP
configuration with each router to the upstream carrier. An iBGP
session is established between my two routers, but I'm confused about
the iBGP.

Say I have a client at 2.2.2.2 and I've assigned him address space
such as 2.2.2.10/29. Previously I would add a route the main router
which serves as that client's gateway such as:

ip route 2.2.2.10 255.255.255.248 2.2.2.2

On my other main router, so that the client subnet was reachable from
there too, I would add:

ip route 2.2.2.10 255.255.255.248 <ip of the first main router I
mentioned>

This has always worked and continues to work. My question is, now
that the iBGP session is established, shouldn't a static route on one
router automatically propagate over to the other router so that I
don't have to add a static route to the second router? I have no
prefix-lists in place over the iBGP session. I guess I was expecting
that all of one routers static routes would propagate over to the
other router. If that's not the case, how do I control that?


Barry Margolin 11-09-2007 02:49 AM

Re: iBGP Advertisements
 
In article <1194566776.012931.311440@e34g2000pro.googlegroups .com>,
Ryan <ryan.parthemore@gmail.com> wrote:

> I'm pretty new to the world of BGP. I have two main routers as a
> small ISP, each with a connection to an upstream carrier. I'm using
> address space provided by one of those carriers and the two main
> routers are on different subnets. All appears well with the eBGP
> configuration with each router to the upstream carrier. An iBGP
> session is established between my two routers, but I'm confused about
> the iBGP.
>
> Say I have a client at 2.2.2.2 and I've assigned him address space
> such as 2.2.2.10/29. Previously I would add a route the main router
> which serves as that client's gateway such as:
>
> ip route 2.2.2.10 255.255.255.248 2.2.2.2
>
> On my other main router, so that the client subnet was reachable from
> there too, I would add:
>
> ip route 2.2.2.10 255.255.255.248 <ip of the first main router I
> mentioned>
>
> This has always worked and continues to work. My question is, now
> that the iBGP session is established, shouldn't a static route on one
> router automatically propagate over to the other router so that I
> don't have to add a static route to the second router? I have no
> prefix-lists in place over the iBGP session. I guess I was expecting
> that all of one routers static routes would propagate over to the
> other router. If that's not the case, how do I control that?


You need a "redistribute static" statement in your BGP configuration to
tell it to propagate all the static routes through BGP.

--
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***
*** PLEASE don't copy me on replies, I'll read them in the group ***


All times are GMT. The time now is 08:21 AM.

Powered by vBulletin®. Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO ©2010, Crawlability, Inc.